Characterization and Activity of Unsupported Ni-Mo Sulfide Catalysts in HDN/HDS Reactions

Abstract

Sulfided Ni-Mo catalysts prepared by homogeneous sulfide precipitation (HSP) and impregnated thiosalt decomposition (ITD) methods were used in thiophene HDS, pyridine HDN, and simultaneous HDS/HDN reactions. All catalysts were characterized by BET surface area measurement, X-ray diffraction, laser Raman spectroscopy, and X-ray photoelectron spectroscopy. The effect of various reaction parameters such as catalyst composition, method of catalyst synthesis, reaction temperature, and reaction pressure on catalytic behavior has been investigated. The inhibition/enhancement effects in simultaneous HDS/HDN reactions were also examined. The studies conducted over the unsupported catalysts present trends very similar to those obtained over the supported catalysts and suggest the intrinsic nature of active sites to be essentially independent of the support.

X-ray absorption near edge structure and X-ray photo electron spectroscopy analyses of NiMo/Al2O3 catalysts containing boron and phosphorus

“…The higher the percentage of sulfur in the form of the oxidation state of −2, the higher the extent of sulfidation and hence catalyst activity. The peak at the binding energy (BE) of 162.5 ± 0.2 eV indicates the formation of Ni Mo S phase or NiS [39] due to OSS of −2, which is close to the value reported in the literature [35,38,39,50,53,55]. Another peak at a higher BE (169.3) was also observed.…”

“…XPS results can be quantified for obtaining relative surface concentrations either by intensity or by peak area [38]. The ratio of peak area of A Mo3d /A Al2p and A Ni2p /A Al2p are usually used to study the dispersion of Mo and Ni on the support [39]).…”

Raman Spectroscopy of Nickel Sulfide Ni3S2

“…The reported Raman spectra for the heazlewoodite-phase Ni 3 S 2 conflict with each other. [4][5][6][7] In addition, the Raman spectrum for the high-temperature cubic-phase Ni 3 S 2 has never been reported.…”

Hydrodeoxygenation of benzofuran over sulfided and reduced Ni–Mo/γ-Al2O3 catalysts: Effect of H2S

“…Alumina-supported catalysts with 15%MoO 3 [18,19] involved impregnation carried out at a pH of 8 and a temperature of 60 • C. The slurry was then dried at 60 • C under vacuum followed by drying in a drying oven over night at 110 • C. The resulting powder was calcined for 4 h at 500 • C under a continuous flow of pure oxygen. The surface area of oxidic samples 184 m 2 /g, was measured using BET method with a Micromeritics ASAP2010 automatically controlled instrument, using nitrogen as adsorbent at liquid nitrogen temperature (−196 • C).…”